zol-2-yl)-4H-1-benzopyran-4-ones 4 is described starting from 2-acetoxybenzoyl chlorides and 1,2-dimethylimidazole. Chromones 4 undergo alkaline ring opening to the corresponding 1-(2-hydroxyphenyl)-2-(1-methyl-1H-imidazol-2-yl)ethenols 5 which give ring closure to 2-substituted 3-(1-methyl-1H-imidazol-2-yl)-4H-1-benzopyran-4-ones or 2,3-dihydro-3-(1-methyl-1H-imidazol-2-yl)-4H-1-benzopyran-4-ones
2-甲基-3-(1-甲基- 1的合成ħ咪唑-2-基)-4- ħ -1-苯并吡喃-4-酮4中描述了从2-乙酰氧基苯甲酰基氯化物和1,2-二甲基咪唑开始。染色体4对相应的1-(2-羟苯基)-2-(1-甲基-1 H-咪唑-2-基)乙烯醇5进行碱性开环,这些环使2取代的3-(1-甲基- 1 H-咪唑-2-基)-4 H -1-苯并吡喃-4-酮或2,3-二氢-3-(1-甲基-1 H-咪唑-2-基)-4 H -1-苯并吡喃-4-ones。可以从色酮4容易地获得相应的色醇和色烯。